/*
 * 统一样式组件（由服务端在返回实验页面时自动注入）。
 * 1) 基础规范使用 :where() 零优先级选择器：只为“页面未设置样式”的元素补齐统一外观，页面自身样式始终优先，不破坏原有设计；
 * 2) .lab-addon 为新增“交互实验区”的统一样式。
 * 配色与平台定稿视觉一致（孔版蓝 / 荧光粉两种油墨，无圆角、无阴影）。
 */
:root {
  --lab-pri: #00558A; --lab-pri2: #0078BF; --lab-ok: #00558A; --lab-bad: #C8006E; --lab-warn: #C8006E;
  --lab-ink: #003A5E; --lab-mute: #436A8C; --lab-line: #CBD8E0; --lab-bg: #ECECE8; --lab-radius: 0;
}
/* ---------- 文字 ---------- */
:where(body) { font-family:"Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif; line-height:1.6; -webkit-text-size-adjust:100%; }
:where(img, video, canvas, svg) { max-width:100%; }
/* ---------- 按钮：统一尺寸、圆角、悬停/点击/禁用状态 ---------- */
:where(button, input[type="button"], input[type="submit"], input[type="reset"]) {
  font:inherit; font-size:14px; line-height:1.4; padding:7px 16px; border-radius:0;
  border:1px solid var(--lab-pri); background:var(--lab-pri); color:#FFFFFF; cursor:pointer;
  transition:filter .15s, transform .05s, box-shadow .15s;
}
:where(button, input[type="button"], input[type="submit"], input[type="reset"]):hover { filter:brightness(1.08); }
:where(button, input[type="button"], input[type="submit"], input[type="reset"]):active { transform:translateY(1px); }
:where(button, input[type="button"], input[type="submit"], input[type="reset"]):disabled { opacity:.5; cursor:not-allowed; filter:none; }
:where(button, input, select, textarea, [tabindex]):focus-visible { outline:2px solid var(--lab-pri2); outline-offset:2px; }
/* ---------- 表单控件 ---------- */
:where(select, input[type="text"], input[type="number"], input[type="search"], input[type="email"], input[type="url"], textarea) {
  font:inherit; font-size:14px; padding:6px 10px; border:1px solid #9DBBD1; border-radius:0; background:#F4F4F1; color:var(--lab-ink); max-width:100%;
}
:where(input[type="range"], input[type="checkbox"], input[type="radio"]) { accent-color:var(--lab-pri); }
:where(input[type="range"]) { max-width:100%; vertical-align:middle; }
:where(input[type="checkbox"], input[type="radio"]) { width:16px; height:16px; vertical-align:-3px; margin-right:4px; }
:where(label) { cursor:pointer; }
:where(table) { border-collapse:collapse; max-width:100%; }

/* ======================= 交互实验区 ======================= */
.lab-addon { max-width:1200px; margin:28px auto; padding:0 16px; color:var(--lab-ink); font-family:"Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif; font-size:14px; line-height:1.65; text-align:left; position:relative; z-index:1; }
.lab-addon * { box-sizing:border-box; }
.lab-addon.la-top { max-width:none; margin:0 0 22px; padding:0; }  /* 放在实验主体之前（第 7 章视频实验区），宽度随实验容器 */
.lab-addon .la-card { background:#F4F4F1; border-radius:0; box-shadow:none; padding:20px 22px; border:1px solid #CBD8E0; }
.lab-addon .la-head { display:flex; align-items:center; gap:10px; margin-bottom:4px; }
.lab-addon .la-head h2 { font-size:20px; margin:0; color:var(--lab-ink); text-shadow:none; text-align:left; }
.lab-addon .la-tag { font-size:13px; background:#E1EAF0; color:#00558A; border:1px solid #CBD8E0; border-radius:0; padding:1px 10px; }
.lab-addon .la-desc { color:var(--lab-mute); font-size:14px; margin:0 0 12px; }
.lab-addon .la-grid { display:grid; grid-template-columns:repeat(auto-fit, minmax(320px, 1fr)); gap:14px; }
.lab-addon .la-block { border:1px solid var(--lab-line); border-radius:0; padding:14px 16px; background:var(--lab-bg); min-width:0; }
.lab-addon .la-block h3 { font-size:15px; margin:0 0 8px; color:var(--lab-pri); display:flex; align-items:center; gap:6px; text-align:left; }
.lab-addon .la-block h3 .no { display:inline-flex; width:20px; height:20px; border-radius:50%; background:var(--lab-pri); color:#FFFFFF; font-size:13px; align-items:center; justify-content:center; flex:0 0 20px; }
.lab-addon .la-row { display:flex; flex-wrap:wrap; align-items:center; gap:8px; margin:6px 0; }
.lab-addon .la-ctl { margin:8px 0; }
.lab-addon .la-ctl > label { display:flex; justify-content:space-between; gap:8px; font-size:14px; margin-bottom:3px; color:var(--lab-ink); }
.lab-addon .la-ctl > label .v { color:var(--lab-pri); font-weight:600; font-variant-numeric:tabular-nums; white-space:nowrap; }
.lab-addon select, .lab-addon input[type=text], .lab-addon input[type=number], .lab-addon textarea { width:100%; font:inherit; font-size:14px; padding:6px 9px; border:1px solid #9DBBD1; border-radius:0; background:#F4F4F1; color:var(--lab-ink); }
.lab-addon input[type=range] { width:100%; accent-color:var(--lab-pri); }
.lab-addon .la-btn { display:inline-flex; align-items:center; gap:6px; font:inherit; font-size:14px; font-weight:600; padding:7px 16px; border-radius:0; border:1px solid var(--lab-pri); background:var(--lab-pri); color:#FFFFFF; cursor:pointer; }
.lab-addon .la-btn.sec { background:#F4F4F1; color:var(--lab-pri); }
.lab-addon .la-btn.sm { padding:3px 10px; font-size:13px; font-weight:500; }
.lab-addon .la-btn:disabled { opacity:.5; cursor:not-allowed; }
.lab-addon .la-chips { display:flex; flex-wrap:wrap; gap:6px; }
.lab-addon .la-chip { display:inline-flex; align-items:center; gap:4px; border:1px solid #9DBBD1; background:#F4F4F1; border-radius:0; padding:4px 10px; font-size:14px; cursor:pointer; user-select:none; }
.lab-addon .la-chip input { margin:0; }
.lab-addon .la-chip.on, .lab-addon .la-chip:has(input:checked) { border-color:var(--lab-pri); background:var(--lab-pri); color:#FFFFFF; }
.lab-addon .la-out { margin-top:10px; background:#F4F4F1; border:1px solid var(--lab-line); border-radius:0; padding:10px 12px; font-size:14px; }
.lab-addon .la-out:empty { display:none; }
.lab-addon .la-ok { color:var(--lab-ok); font-weight:600; }
.lab-addon .la-bad { color:var(--lab-bad); font-weight:600; }
.lab-addon .la-item { display:grid; grid-template-columns:minmax(0, 1fr) 150px; gap:8px; align-items:center; padding:6px 0; border-top:1px dashed #CBD8E0; }
.lab-addon .la-item:first-of-type { border-top:0; }
.lab-addon .la-item label { font-size:14px; }
.lab-addon .la-item .ex { grid-column:1 / -1; font-size:13px; color:var(--lab-mute); }
.lab-addon .la-sort li { display:flex; align-items:center; gap:6px; background:#F4F4F1; border:1px solid var(--lab-line); border-radius:0; padding:5px 8px; margin:4px 0; font-size:14px; }
.lab-addon .la-sort { list-style:none; padding:0; margin:0; counter-reset:s; }
.lab-addon .la-sort li::before { counter-increment:s; content:counter(s); width:20px; height:20px; border-radius:50%; background:#E1EAF0; color:var(--lab-pri); font-size:13px; display:inline-flex; align-items:center; justify-content:center; flex:0 0 20px; }
.lab-addon .la-sort li span { flex:1; }
.lab-addon .la-bars .b { display:grid; grid-template-columns:90px 1fr 70px; align-items:center; gap:8px; margin:5px 0; font-size:14px; }
.lab-addon .la-bars .t { height:12px; background:#E4E4DF; border-radius:0; overflow:hidden; }
.lab-addon .la-bars .t i { display:block; height:100%; border-radius:0; transition:width .3s; }
.lab-addon table.la-tb { width:100%; border-collapse:collapse; font-size:14px; background:#F4F4F1; }
.lab-addon table.la-tb th, .lab-addon table.la-tb td { border:1px solid var(--lab-line); padding:6px 8px; text-align:left; vertical-align:top; }
.lab-addon table.la-tb th { background:#E1EAF0; color:var(--lab-ink); font-weight:600; }
.lab-addon table.la-tb td { color:var(--lab-ink); background:#F4F4F1; }
.lab-addon h2, .lab-addon h3, .lab-addon label, .lab-addon p { letter-spacing:normal; text-transform:none; }
.lab-addon .la-note { font-size:13px; color:var(--lab-mute); margin-top:6px; }
@media (max-width: 560px) {
  .lab-addon .la-item { grid-template-columns:1fr; }
  .lab-addon .la-card { padding:14px; }
}